[PATCH 11/14] mmc: sh_mmcif: handle highmem pages

Christoph Hellwig
2019-02-12T07:25:25Z

Instead of setting up a kernel pointer to track the current PIO address,
track the offset in the current page, and do an atomic kmap for the page
while doing the actual PIO operations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/mmc/host/sh_mmcif.c | 59 +++++++++++++++++++++++--------------
1 file changed, 37 insertions(+), 22 deletions(-)

diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
index 81bd9afb0980..24c3f13bafdb 100644
--- a/drivers/mmc/host/sh_mmcif.c
+++ b/drivers/mmc/host/sh_mmcif.c
@@ -228,7 +228,7 @@ struct sh_mmcif_host {
bool dying;
long timeout;
void __iomem *addr;
- u32 *pio_ptr;
+ u32 pio_offset;
spinlock_t lock; /* protect sh_mmcif_host::state */
enum sh_mmcif_state state;
enum sh_mmcif_wait_for wait_for;
@@ -595,7 +595,7 @@ static int sh_mmcif_error_manage(struct sh_mmcif_host *host)
return ret;
}

-static bool sh_mmcif_next_block(struct sh_mmcif_host *host, u32 *p)
+static bool sh_mmcif_next_block(struct sh_mmcif_host *host)
{
struct mmc_data *data = host->mrq->data;

@@ -606,10 +606,10 @@ static bool sh_mmcif_next_block(struct sh_mmcif_host *host, u32 *p)

if (host->sg_blkidx == data->sg->length) {
host->sg_blkidx = 0;
- if (++host->sg_idx < data->sg_len)
- host->pio_ptr = sg_virt(++data->sg);
- } else {
- host->pio_ptr = p;
+ if (++host->sg_idx < data->sg_len) {
+ data->sg++;
+ host->pio_offset = data->sg->offset / 4;
+ }
}

return host->sg_idx != data->sg_len;
@@ -631,8 +631,8 @@ static bool sh_mmcif_read_block(struct sh_mmcif_host *host)
{
struct device *dev = sh_mmcif_host_to_dev(host);
struct mmc_data *data = host->mrq->data;
- u32 *p = sg_virt(data->sg);
- int i;
+ u32 *p;
+ int off, i;

if (host->sd_error) {
data->error = sh_mmcif_error_manage(host);
@@ -640,8 +640,11 @@ static bool sh_mmcif_read_block(struct sh_mmcif_host *host)
return false;
}

+ p = sg_kmap_atomic(data->sg);
+ off = data->sg->offset / 4;
for (i = 0; i < host->blocksize / 4; i++)
- *p++ = sh_mmcif_readl(host->addr, MMCIF_CE_DATA);
+ p[off++] = sh_mmcif_readl(host->addr, MMCIF_CE_DATA);
+ sg_kunmap_atomic(data->sg, p);

/* buffer read end */
sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MBUFRE);
@@ -664,7 +667,7 @@ static void sh_mmcif_multi_read(struct sh_mmcif_host *host,
host->wait_for = MMCIF_WAIT_FOR_MREAD;
host->sg_idx = 0;
host->sg_blkidx = 0;
- host->pio_ptr = sg_virt(data->sg);
+ host->pio_offset = data->sg->offset / 4;

sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MBUFREN);
}
@@ -673,7 +676,7 @@ static bool sh_mmcif_mread_block(struct sh_mmcif_host *host)
{
struct device *dev = sh_mmcif_host_to_dev(host);
struct mmc_data *data = host->mrq->data;
- u32 *p = host->pio_ptr;
+ u32 *p;
int i;

if (host->sd_error) {
@@ -684,10 +687,14 @@ static bool sh_mmcif_mread_block(struct sh_mmcif_host *host)

BUG_ON(!data->sg->length);

- for (i = 0; i < host->blocksize / 4; i++)
- *p++ = sh_mmcif_readl(host->addr, MMCIF_CE_DATA);
+ p = sg_kmap_atomic(data->sg);
+ for (i = 0; i < host->blocksize / 4; i++) {
+ p[host->pio_offset++] =
+ sh_mmcif_readl(host->addr, MMCIF_CE_DATA);
+ }
+ sg_kunmap_atomic(data->sg, p);

- if (!sh_mmcif_next_block(host, p))
+ if (!sh_mmcif_next_block(host))
return false;

sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MBUFREN);
@@ -711,8 +718,8 @@ static bool sh_mmcif_write_block(struct sh_mmcif_host *host)
{
struct device *dev = sh_mmcif_host_to_dev(host);
struct mmc_data *data = host->mrq->data;
- u32 *p = sg_virt(data->sg);
- int i;
+ u32 *p;
+ int off, i;

if (host->sd_error) {
data->error = sh_mmcif_error_manage(host);
@@ -720,8 +727,11 @@ static bool sh_mmcif_write_block(struct sh_mmcif_host *host)
return false;
}

+ p = sg_kmap_atomic(data->sg);
+ off = data->sg->offset / 4;
for (i = 0; i < host->blocksize / 4; i++)
- sh_mmcif_writel(host->addr, MMCIF_CE_DATA, *p++);
+ sh_mmcif_writel(host->addr, MMCIF_CE_DATA, p[off++]);
+ sg_kunmap_atomic(data->sg, p);

/* buffer write end */
sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MDTRANE);
@@ -744,7 +754,7 @@ static void sh_mmcif_multi_write(struct sh_mmcif_host *host,
host->wait_for = MMCIF_WAIT_FOR_MWRITE;
host->sg_idx = 0;
host->sg_blkidx = 0;
- host->pio_ptr = sg_virt(data->sg);
+ host->pio_offset = data->sg->offset / 4;

sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MBUFWEN);
}
@@ -753,7 +763,7 @@ static bool sh_mmcif_mwrite_block(struct sh_mmcif_host *host)
{
struct device *dev = sh_mmcif_host_to_dev(host);
struct mmc_data *data = host->mrq->data;
- u32 *p = host->pio_ptr;
+ u32 *p;
int i;

if (host->sd_error) {
@@ -764,10 +774,14 @@ static bool sh_mmcif_mwrite_block(struct sh_mmcif_host *host)

BUG_ON(!data->sg->length);

- for (i = 0; i < host->blocksize / 4; i++)
- sh_mmcif_writel(host->addr, MMCIF_CE_DATA, *p++);
+ p = sg_kmap_atomic(data->sg);
+ for (i = 0; i < host->blocksize / 4; i++) {
+ sh_mmcif_writel(host->addr, MMCIF_CE_DATA,
+ p[host->pio_offset++]);
+ }
+ sg_kunmap_atomic(data->sg, p);

- if (!sh_mmcif_next_block(host, p))
+ if (!sh_mmcif_next_block(host))
return false;

sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MBUFWEN);
@@ -1424,6 +1438,7 @@ static int sh_mmcif_probe(struct platform_device *pdev)
spin_lock_init(&host->lock);

mmc->ops = &sh_mmcif_ops;
+ mmc->need_kmap = 1;
sh_mmcif_init_ocr(host);

mmc->caps |= MMC_CAP_MMC_HIGHSPEED | MMC_CAP_WAIT_WHILE_BUSY;
--
2.20.1